A human health risk assessment of heavy metals in agricultural soils of Yanqi Basin, Silk Road Economic Belt, China

ABSTRACT

A total of 195 farmland soil samples were collected in Yanqi Basin, Xinjiang, northwest China, and the concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn were analyzed for their concentrations and pollution levels using the Nemerow comprehensive index. The health risk assessment model introduced by USEPA was utilized to evaluate the human health risks of heavy metals. Results indicated that the average concentrations of these seven metals were lower than the allowed soil environmental quality standards of China, while the average concentrations of Cd, Cr, Ni, Pb and Zn exceeded the background values of irrigation soils in Xinjiang. The average contamination factor (CF) for Pb indicated the heavy pollution, whereas the CF for Cd, Zn, Ni, Cu and Cr indicated the moderate pollution. The average PLI of heavy metals indicated the low pollution. The non-carcinogenic hazard index were below the threshold values, and the total carcinogenic risks due to As and Cr were within the acceptable range for both children and adults. As and Pb were the main non-carcinogenic factors, while As was the main carcinogenic factor in the study area. Special attentions should be paid to these priority control metals in order to target the lowest threats to human health.

KEYWORDS:

• farmland soils
• heavy metal pollution
• health risk assessment
• Yanqi Basin

Acknowledgments

The authors would like to thank the editors and anonymous reviewers for providing numerous constructive comments that significantly improved the article.

Funding

This work was supported jointly by the National Natural Science Foundation of China (No. 41561073), the “13th Five-Year” Plan for Key Discipline Geography Bidding Project (No. 17SDKD0707), Xinjiang Normal University, and Fund for the Training Program of Distinguished Young Scientists of Xinjiang (No. qn2015jq003).